net.sourceforge.jiu.color.adjustment

Class Brightness


public class Brightness
extends LookupTableOperation

Adjusts the brightness of an image.

The brightness change is specified as a percentage value between -100 and 100. -100 will make the resulting image black, 0 will leave it unchanged, 100 will make it white.

Supported image types

Usage examples

Both examples make the input image 30 percent brighter.

If all you want is to create a new image with adjusted brightness from the image data of an existing image, simply use the static helper method:

PixelImage adjustedImage = Brightness.adjust(inputImage, 30);
This leaves the original image inputImage unchanged and allocates a second image object which is here assigned to the variable adjustedImage.

If you want more control over parameters, create your own Brightness object. You can then reuse image objects, e.g. to write the adjusted image data to the original image object:

 Brightness brightness = new Brightness();
 brightness.setInputImage(image);
 brightness.setOutputImage(image);
 brightness.setBrightness(30);
 brightness.process();
 // at this point, image will contain the adjusted image data,
 // the original data wil be overwritten 
 

Author:
Marco Schmidt

Field Summary

private int
brightness

Fields inherited from class net.sourceforge.jiu.ops.LookupTableOperation

intTables, numTables

Fields inherited from class net.sourceforge.jiu.ops.ImageToImageOperation

canInAndOutBeEqual, inputImage, outputImage

Fields inherited from class net.sourceforge.jiu.ops.Operation

abort, progressListeners

Method Summary

static PixelImage
adjust(PixelImage input, int percentage)
This static helper method is more simple to use when all you need are the standard options.
private int[]
createLookupTable(int numSamples, int brightness)
Creates a lookup table that holds all new values for samples 0 to numSamples - 1.
void
process()
This method does the actual work of the operation.
private void
process(Paletted8Image in, Paletted8Image out)
void
setBrightness(int newBrightness)
Sets the brightness adjustment value in percent (between -100 and 100).

Methods inherited from class net.sourceforge.jiu.ops.LookupTableOperation

getNumTables, getTable, prepareImages, process, process, process, setNumTables, setTable, setTables

Methods inherited from class net.sourceforge.jiu.ops.ImageToImageOperation

canInputAndOutputBeEqual, ensureImagesHaveSameResolution, ensureInputImageIsAvailable, ensureOutputImageResolution, getInputImage, getOutputImage, setCanInputAndOutputBeEqual, setInputImage, setOutputImage

Methods inherited from class net.sourceforge.jiu.ops.Operation

addProgressListener, addProgressListeners, getAbort, process, removeProgressListener, setAbort, setProgress, setProgress

Field Details

brightness

private int brightness

Method Details

adjust

public static PixelImage adjust(PixelImage input,
                                int percentage)
This static helper method is more simple to use when all you need are the standard options.
Parameters:
input - the image to work on
percentage - brightness modification, from -100 to 100
Returns:
a new image with adjusted brightness

createLookupTable

private int[] createLookupTable(int numSamples,
                                int brightness)
Creates a lookup table that holds all new values for samples 0 to numSamples - 1.

process

public void process()
            throws MissingParameterException,
                   WrongParameterException
This method does the actual work of the operation. It must be called after all parameters have been given to the operation object.
Overrides:
process in interface LookupTableOperation
Throws:
WrongParameterException - if at least one of the input parameters was not initialized appropriately (values out of the valid interval, etc.)
MissingParameterException - if any mandatory parameter was not given to the operation

process

private void process(Paletted8Image in,
                     Paletted8Image out)

setBrightness

public void setBrightness(int newBrightness)
Sets the brightness adjustment value in percent (between -100 and 100).
Parameters:
newBrightness - the amount of change to be applied to the brightness of the input image